In an uplink coordinated multipoint transmission (CoMP) technology, multiple sectors within a base station or multiple base stations perform joint reception, demodulation, and decoding of uplink data of user equipment (UE), so as to improve coverage performance for edge UE and improve an uplink rate of the UE. For example, a serving cell of UE belongs to a base station 0, coordinated cells belong to base stations 1 to K (K≥1), and the base station 0 and the base stations 1 to K perform joint reception, demodulation, and decoding of uplink data sent by the UE. According to this manner, after completing MAC layer scheduling, the base station 0 sends management information (such as scheduling information about connected UE) to the base stations 1 to K. Afterwards, the UE sends same uplink data to the base station 0 and the base stations 1 to K at the same time. The base stations 1 to K forward the received uplink data to the base station 0. The base station 0 completes joint reception, demodulation, and decoding of the data in a specified time T and performs retransmission scheduling or transmission scheduling according to a result of the joint demodulation and decoding.
In the foregoing process, the base station 0 sets a moment 1 in the specified time T. If the base station 0 receives the uplink data forwarded by the base stations 1 to K before the moment 1, the base station 0 combines the uplink data received by the base station 0 directly from the UE and the uplink data forwarded by the base stations 1 to K, and then performs joint demodulation and decoding. Joint reception, demodulation, and decoding need to be completed in a specified time. Factors such as network congestion and limited network capacity may cause a relatively long delay in data interaction between the base stations. Consequently, the uplink data forwarded by the base stations 1 to K cannot reach the base station 0 in time before the moment 1, and the base station 0 does not have enough time to perform joint demodulation and decoding. In this case, the base station 0 performs demodulation and decoding of the uplink data received directly from the UE.
However, because a correctness rate of a result of separate demodulation and decoding is lower than a correctness rate of a result of joint demodulation and decoding, a data retransmission rate of the UE is high, that is, a volume of uplink data that is successfully transmitted by the UE in unit time is reduced. Consequently, an uplink rate of the UE is reduced.